app.py

import os

from cs50 import SQL
from flask import Flask, flash, redirect, render_template, request, session
from flask_session import Session
from werkzeug.security import check_password_hash, generate_password_hash

from helpers import apology, login_required, lookup, usd

# Configure application
app = Flask(__name__)

# Custom filter
app.jinja_env.filters["usd"] = usd

# Configure session to use filesystem (instead of signed cookies)
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)

# Configure CS50 Library to use SQLite database
db = SQL("sqlite:///finance.db")


@app.after_request
def after_request(response):
    """Ensure responses aren't cached"""
    response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate"
    response.headers["Expires"] = 0
    response.headers["Pragma"] = "no-cache"
    return response


@app.route("/")
@login_required
def index():
    """Show portfolio of stocks"""

    stocks = db.execute("SELECT symbol, SUM(shares) as total_shares FROM transactions WHERE user_id = :user_id GROUP BY symbol HAVING total_shares > 0",
                        user_id=session["user_id"])

    cash = db.execute("SELECT cash FROM users WHERE id = ?", session["user_id"])[0]["cash"]

    total_value = cash
    grand_total = cash

    for stock in stocks:
        quote = lookup(stock["symbol"])
        stock["name"] = quote["name"]
        stock["price"] = quote["price"]
        stock["value"] = stock["price"] * stock["total_shares"]
        total_value += stock["value"]
        grand_total += stock["value"]

    grand_total = usd(grand_total)
    cash = usd(cash)
    return render_template("index.html", stocks=stocks, cash=cash, total_value=total_value, grand_total=grand_total)


@app.route("/buy", methods=["GET", "POST"])
@login_required
def buy():
    """Buy shares of stock"""
    if request.method == 'POST':
        symbol = request.form.get("symbol").upper()
        shares = request.form.get("shares")
        if not symbol:
            return apology("Must include symbol")
        elif not shares or int(shares) <= 0 or not shares.isdigit():
            return apology("Need to include a positive integer number of shares")

        quote = lookup(symbol)
        if quote is None:
            return apology("Invalid Symbol")

        price = quote["price"]
        total_cost = int(shares) * price
        cash = db.execute("SELECT cash FROM users WHERE id = ?", session["user_id"])[0]["cash"]

        if cash < total_cost:
            return apology("insufficient funds")

        # Update users table
        db.execute("UPDATE users SET cash = ? WHERE id = ?", cash - total_cost, session["user_id"])

        # Add purchase to history table
        db.execute("INSERT INTO transactions (user_id, symbol, shares, price) VALUES (?, ?, ?, ?)",
                   session["user_id"], symbol, shares, price)

        flash(f"Bought {shares} shares of {symbol} for {usd(total_cost)}!")
        return redirect("/")

    else:
        return render_template("buy.html")


@app.route("/history")
@login_required
def history():
    """Show history of transactions"""
    transactions = db.execute(
        "SELECT * FROM transactions WHERE user_id = ? ORDER BY timestamp DESC", session["user_id"])

    # for i in transactions:
    # if i["shares"] < 0:
    # i["type"] = "sell"
    # else:
    # i["type"] = "buy"

    return render_template("history.html", transactions=transactions)


@app.route("/login", methods=["GET", "POST"])
def login():
    """Log user in"""

    # Forget any user_id
    session.clear()

    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":
        # Ensure username was submitted
        if not request.form.get("username"):
            return apology("must provide username", 403)

        # Ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password", 403)

        # Query database for username
        rows = db.execute(
            "SELECT * FROM users WHERE username = ?", request.form.get("username")
        )

        # Ensure username exists and password is correct
        if len(rows) != 1 or not check_password_hash(
            rows[0]["hash"], request.form.get("password")
        ):
            return apology("invalid username and/or password", 403)

        # Remember which user has logged in
        session["user_id"] = rows[0]["id"]

        # Redirect user to home page
        return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("login.html")


@app.route("/logout")
def logout():
    """Log user out"""

    # Forget any user_id
    session.clear()

    # Redirect user to login form
    return redirect("/")


@app.route("/quote", methods=["GET", "POST"])
@login_required
def quote():
    """Get stock quote."""
    if request.method == "POST":
        # look up the stock symbol by calling lookup function and display results
        # if successful, should return dictionary with name, price, symbol
        if lookup(request.form.get("symbol")) != None:
            info = lookup(request.form.get("symbol"))
            name = info.get("name")
            price = info.get("price")
            symbol = info.get("symbol")

            details = f"A share of {name} ({symbol}) costs"

            return render_template("info.html", name=details, price=price)
        # if unsuccessful, function returns none
        else:
            return apology("Invalid Symbol")

    else:
        # display form to request a stock quote
        return render_template("quote.html")


@app.route("/register", methods=["GET", "POST"])
def register():
    """Register user"""
    if request.method == "POST":
        # If any field is left blank
        # Ensure username was submitted
        if not request.form.get("username"):
            return apology("must provide username")

        # Ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password")
        # Check if Password is a valid entry

        else:
            # check if password and confirmation matches
            if request.form.get("password") != request.form.get("confirmation"):
                return apology("password and confirmation doesn't match")

            else:
                # check if username is already taken
                if len(db.execute("SELECT username FROM users WHERE username = ?", request.form.get("username"))) != 0:
                    return apology("Username already taken")
                else:
                    password_hash = generate_password_hash(request.form.get("password"))

                    db.execute("INSERT INTO users (username, hash) VALUES (?, ?)",
                               request.form.get("username"), password_hash)

                    return redirect("/")

    else:
        return render_template("register.html")


@app.route("/sell", methods=["GET", "POST"])
@login_required
def sell():
    """Sell shares of stock"""
    stocks = db.execute("SELECT symbol, SUM(shares) as total_shares FROM transactions WHERE user_id = :user_id GROUP BY symbol HAVING total_shares > 0",
                        user_id=session["user_id"])
    cash = db.execute("SELECT cash FROM users WHERE id = ?", session["user_id"])[0]["cash"]

    if request.method == "POST":
        symbol = request.form.get("symbol").upper()
        shares = request.form.get("shares")
        if not symbol:
            return apology("Need to include symbol")
        elif not shares or int(shares) <= 0 or not shares.isdigit():
            return apology("Need to provide a positive integer of shares")
        else:
            shares = int(shares)

        for stock in stocks:
            if stock["symbol"] == symbol:
                if stock["total_shares"] < shares:
                    return apology("not enough shares")
                else:
                    quote = lookup(symbol)
                    if quote is None:
                        return apology("symbol not found")
                    price = quote["price"]
                    total_sale = shares * price

                # Update users table
                db.execute("UPDATE users SET cash = ? WHERE id = ?",
                           cash + total_sale, session["user_id"])

                # Update sale to transaction table
                db.execute("INSERT INTO transactions (user_id, symbol, shares, price) VALUES (?, ?, ?, ?)",
                           session["user_id"], symbol, -shares, price)

                flash(f"Sold {shares} shares of {symbol} for {usd(total_sale)}!")
                return redirect("/")

        return apology("symbol not found")
    else:
        return render_template("sell.html", stocks=stocks)